The variety ‘Kakegawa AU12’ originated from a cross made in March 2001 in Misato, Japan. The female parent was a tetraploid Osteospermum sp. developed using the variety ‘Seikilrem’ (U.S. Plant Pat. No. 13,407). The male parent was an unnamed Dimorphotheca sinuate with small, yellow flowers, shiny petals, long internodes and prostrate habit. Seed from this cross was sown in June 2001 and plants were transplanted to the outdoor field. In October 2001, single-plant selections were made for vegetative propagation using plant habit and flower color as selection criteria. One selection, designated breeder code M2-123, became the new variety ‘Kakegawa AU12’. The traits of ‘Kakegawa AU12’ were found to be reproducible, stable and true to type in successive generations of asexual propagation.